X-Rays are a form of electromagnetic radiation, as is visible light, but with some different characteristics.

The important characteristic of X-Rays is that these can penetrate or pass through the human body but cannot pass through bones, hard items like bullets etc.

This effect produces shadow-like images of structures such as bones, bullets etc. on a photographic plate. This helps to understand the inner details of body such as presence of foreign hard materials (bullets etc.) or any fracture in the bones.

X-rays are a form of electromagnetic radiation, similar to visible light. Unlike light, however, x-rays have higher energy and can pass through most objects, including the body. Medical x-rays are used to generate images of tissues and structures inside the body. 

If x-rays travelling through the body also pass through an x-ray detector on the other side of the patient, an image will be formed that represents the “shadows” formed by the objects inside the body.

One type of x-ray detector is photographic film, but there are many other types of detectors that are used to produce digital images. The x-ray images that result from this process are called radiographs.